| /** |
| * @file int64.c |
| * |
| * @brief Functions for 64-bit integer computations. |
| * |
| * 21-jan-1998: David Perkins <dperkins@dsperkins.com> |
| */ |
| |
| #include <net-snmp/net-snmp-config.h> |
| #include <sys/types.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <ctype.h> |
| #if HAVE_STRING_H |
| #include <string.h> |
| #else |
| #include <strings.h> |
| #endif |
| #if HAVE_WINSOCK_H |
| #include <winsock.h> |
| #endif |
| |
| #include <net-snmp/types.h> |
| #include <net-snmp/library/int64.h> |
| #include <net-snmp/library/snmp_assert.h> |
| #include <net-snmp/library/snmp_debug.h> |
| #include <net-snmp/library/snmp_logging.h> |
| |
| /** |
| * Divide an unsigned 64-bit integer by 10. |
| * |
| * @param[in] u64 Number to be divided. |
| * @param[out] pu64Q Quotient. |
| * @param[out] puR Remainder. |
| */ |
| void |
| divBy10(U64 u64, U64 * pu64Q, unsigned int *puR) |
| { |
| unsigned long ulT; |
| unsigned long ulQ; |
| unsigned long ulR; |
| |
| /* |
| * top 16 bits |
| */ |
| ulT = (u64.high >> 16) & 0x0ffff; |
| ulQ = ulT / 10; |
| ulR = ulT % 10; |
| pu64Q->high = ulQ << 16; |
| |
| /* |
| * next 16 |
| */ |
| ulT = (u64.high & 0x0ffff); |
| ulT += (ulR << 16); |
| ulQ = ulT / 10; |
| ulR = ulT % 10; |
| pu64Q->high = pu64Q->high | ulQ; |
| |
| /* |
| * next 16 |
| */ |
| ulT = ((u64.low >> 16) & 0x0ffff) + (ulR << 16); |
| ulQ = ulT / 10; |
| ulR = ulT % 10; |
| pu64Q->low = ulQ << 16; |
| |
| /* |
| * final 16 |
| */ |
| ulT = (u64.low & 0x0ffff); |
| ulT += (ulR << 16); |
| ulQ = ulT / 10; |
| ulR = ulT % 10; |
| pu64Q->low = pu64Q->low | ulQ; |
| |
| *puR = (unsigned int) (ulR); |
| } |
| |
| /** |
| * Multiply an unsigned 64-bit integer by 10. |
| * |
| * @param[in] u64 Number to be multiplied. |
| * @param[out] pu64P Product. |
| */ |
| void |
| multBy10(U64 u64, U64 * pu64P) |
| { |
| unsigned long ulT; |
| unsigned long ulP; |
| unsigned long ulK; |
| |
| /* |
| * lower 16 bits |
| */ |
| ulT = u64.low & 0x0ffff; |
| ulP = ulT * 10; |
| ulK = ulP >> 16; |
| pu64P->low = ulP & 0x0ffff; |
| |
| /* |
| * next 16 |
| */ |
| ulT = (u64.low >> 16) & 0x0ffff; |
| ulP = (ulT * 10) + ulK; |
| ulK = ulP >> 16; |
| pu64P->low = (ulP & 0x0ffff) << 16 | pu64P->low; |
| |
| /* |
| * next 16 bits |
| */ |
| ulT = u64.high & 0x0ffff; |
| ulP = (ulT * 10) + ulK; |
| ulK = ulP >> 16; |
| pu64P->high = ulP & 0x0ffff; |
| |
| /* |
| * final 16 |
| */ |
| ulT = (u64.high >> 16) & 0x0ffff; |
| ulP = (ulT * 10) + ulK; |
| ulK = ulP >> 16; |
| pu64P->high = (ulP & 0x0ffff) << 16 | pu64P->high; |
| } |
| |
| /** |
| * Add an unsigned 16-bit int to an unsigned 64-bit integer. |
| * |
| * @param[in,out] pu64 Number to be incremented. |
| * @param[in] u16 Amount to add. |
| * |
| */ |
| void |
| incrByU16(U64 * pu64, unsigned int u16) |
| { |
| incrByU32(pu64, u16); |
| } |
| |
| /** |
| * Add an unsigned 32-bit int to an unsigned 64-bit integer. |
| * |
| * @param[in,out] pu64 Number to be incremented. |
| * @param[in] u32 Amount to add. |
| * |
| */ |
| void |
| incrByU32(U64 * pu64, unsigned int u32) |
| { |
| uint32_t tmp; |
| |
| tmp = pu64->low; |
| pu64->low = (uint32_t)(tmp + u32); |
| if (pu64->low < tmp) |
| pu64->high = (uint32_t)(pu64->high + 1); |
| } |
| |
| /** |
| * Subtract two 64-bit numbers. |
| * |
| * @param[in] pu64one Number to start from. |
| * @param[in] pu64two Amount to subtract. |
| * @param[out] pu64out pu64one - pu64two. |
| */ |
| void |
| u64Subtract(const U64 * pu64one, const U64 * pu64two, U64 * pu64out) |
| { |
| int carry; |
| |
| carry = pu64one->low < pu64two->low; |
| pu64out->low = (uint32_t)(pu64one->low - pu64two->low); |
| pu64out->high = (uint32_t)(pu64one->high - pu64two->high - carry); |
| } |
| |
| /** |
| * Add two 64-bit numbers. |
| * |
| * @param[in] pu64one Amount to add. |
| * @param[in,out] pu64out pu64out += pu64one. |
| */ |
| void |
| u64Incr(U64 * pu64out, const U64 * pu64one) |
| { |
| pu64out->high = (uint32_t)(pu64out->high + pu64one->high); |
| incrByU32(pu64out, pu64one->low); |
| } |
| |
| /** |
| * Add the difference of two 64-bit numbers to a 64-bit counter. |
| * |
| * @param[in] pu64one |
| * @param[in] pu64two |
| * @param[out] pu64out pu64out += (pu64one - pu64two) |
| */ |
| void |
| u64UpdateCounter(U64 * pu64out, const U64 * pu64one, const U64 * pu64two) |
| { |
| U64 tmp; |
| |
| u64Subtract(pu64one, pu64two, &tmp); |
| u64Incr(pu64out, &tmp); |
| } |
| |
| /** |
| * Copy a 64-bit number. |
| * |
| * @param[in] pu64two Number to be copied. |
| * @param[out] pu64one Where to store the copy - *pu64one = *pu64two. |
| */ |
| void |
| u64Copy(U64 * pu64one, const U64 * pu64two) |
| { |
| *pu64one = *pu64two; |
| } |
| |
| /** |
| * Set an unsigned 64-bit number to zero. |
| * |
| * @param[in] pu64 Number to be zeroed. |
| */ |
| void |
| zeroU64(U64 * pu64) |
| { |
| pu64->low = 0; |
| pu64->high = 0; |
| } |
| |
| /** |
| * Check if an unsigned 64-bit number is zero. |
| * |
| * @param[in] pu64 Number to be checked. |
| */ |
| int |
| isZeroU64(const U64 * pu64) |
| { |
| return pu64->low == 0 && pu64->high == 0; |
| } |
| |
| /** |
| * check the old and new values of a counter64 for 32bit wrapping |
| * |
| * @param adjust : set to 1 to auto-increment new_val->high |
| * if a 32bit wrap is detected. |
| * |
| * @param old_val |
| * @param new_val |
| * |
| * @note |
| * The old and new values must be be from within a time period |
| * which would only allow the 32bit portion of the counter to |
| * wrap once. i.e. if the 32bit portion of the counter could |
| * wrap every 60 seconds, the old and new values should be compared |
| * at least every 59 seconds (though I'd recommend at least every |
| * 50 seconds to allow for timer inaccuracies). |
| * |
| * @retval 64 : 64bit wrap |
| * @retval 32 : 32bit wrap |
| * @retval 0 : did not wrap |
| * @retval -1 : bad parameter |
| * @retval -2 : unexpected high value (changed by more than 1) |
| */ |
| int |
| netsnmp_c64_check_for_32bit_wrap(struct counter64 *old_val, |
| struct counter64 *new_val, |
| int adjust) |
| { |
| if( (NULL == old_val) || (NULL == new_val) ) |
| return -1; |
| |
| DEBUGMSGTL(("9:c64:check_wrap", "check wrap 0x%0x.0x%0x 0x%0x.0x%0x\n", |
| old_val->high, old_val->low, new_val->high, new_val->low)); |
| |
| /* |
| * check for wraps |
| */ |
| if ((new_val->low >= old_val->low) && |
| (new_val->high == old_val->high)) { |
| DEBUGMSGTL(("9:c64:check_wrap", "no wrap\n")); |
| return 0; |
| } |
| |
| /* |
| * low wrapped. did high change? |
| */ |
| if (new_val->high == old_val->high) { |
| DEBUGMSGTL(("c64:check_wrap", "32 bit wrap\n")); |
| if (adjust) |
| new_val->high = (uint32_t)(new_val->high + 1); |
| return 32; |
| } |
| else if (new_val->high == (uint32_t)(old_val->high + 1)) { |
| DEBUGMSGTL(("c64:check_wrap", "64 bit wrap\n")); |
| return 64; |
| } |
| |
| return -2; |
| } |
| |
| /** |
| * update a 64 bit value with the difference between two (possibly) 32 bit vals |
| * |
| * @param prev_val : the 64 bit current counter |
| * @param old_prev_val : the (possibly 32 bit) previous value |
| * @param new_val : the (possible 32bit) new value |
| * @param need_wrap_check: pointer to integer indicating if wrap check is needed |
| * flag may be cleared if 64 bit counter is detected |
| * |
| * @note |
| * The old_prev_val and new_val values must be be from within a time |
| * period which would only allow the 32bit portion of the counter to |
| * wrap once. i.e. if the 32bit portion of the counter could |
| * wrap every 60 seconds, the old and new values should be compared |
| * at least every 59 seconds (though I'd recommend at least every |
| * 50 seconds to allow for timer inaccuracies). |
| * |
| * Suggested use: |
| * |
| * static needwrapcheck = 1; |
| * static counter64 current, prev_val, new_val; |
| * |
| * your_functions_to_update_new_value(&new_val); |
| * if (0 == needwrapcheck) |
| * memcpy(current, new_val, sizeof(new_val)); |
| * else { |
| * netsnmp_c64_check32_and_update(¤t,&new,&prev,&needwrapcheck); |
| * memcpy(prev_val, new_val, sizeof(new_val)); |
| * } |
| * |
| * |
| * @retval 0 : success |
| * @retval -1 : error checking for 32 bit wrap |
| * @retval -2 : look like we have 64 bit values, but sums aren't consistent |
| */ |
| int |
| netsnmp_c64_check32_and_update(struct counter64 *prev_val, struct counter64 *new_val, |
| struct counter64 *old_prev_val, int *need_wrap_check) |
| { |
| int rc; |
| |
| /* |
| * counters are 32bit or unknown (which we'll treat as 32bit). |
| * update the prev values with the difference between the |
| * new stats and the prev old_stats: |
| * prev->stats += (new->stats - prev->old_stats) |
| */ |
| if ((NULL == need_wrap_check) || (0 != *need_wrap_check)) { |
| rc = netsnmp_c64_check_for_32bit_wrap(old_prev_val,new_val, 1); |
| if (rc < 0) { |
| snmp_log(LOG_ERR,"c64 32 bit check failed\n"); |
| return -1; |
| } |
| } |
| else |
| rc = 0; |
| |
| /* |
| * update previous values |
| */ |
| (void) u64UpdateCounter(prev_val, new_val, old_prev_val); |
| |
| /* |
| * if wrap check was 32 bit, undo adjust, now that prev is updated |
| */ |
| if (32 == rc) { |
| /* |
| * check wrap incremented high, so reset it. (Because having |
| * high set for a 32 bit counter will confuse us in the next update). |
| */ |
| netsnmp_assert(1 == new_val->high); |
| new_val->high = 0; |
| } |
| else if (64 == rc) { |
| /* |
| * if we really have 64 bit counters, the summing we've been |
| * doing for prev values should be equal to the new values. |
| */ |
| if ((prev_val->low != new_val->low) || |
| (prev_val->high != new_val->high)) { |
| snmp_log(LOG_ERR, "looks like a 64bit wrap, but prev!=new\n"); |
| return -2; |
| } |
| else if (NULL != need_wrap_check) |
| *need_wrap_check = 0; |
| } |
| |
| return 0; |
| } |
| |
| /** Convert an unsigned 64-bit number to ASCII. */ |
| void |
| printU64(char *buf, /* char [I64CHARSZ+1]; */ |
| const U64 * pu64) |
| { |
| U64 u64a; |
| U64 u64b; |
| |
| char aRes[I64CHARSZ + 1]; |
| unsigned int u; |
| int j; |
| |
| u64a = *pu64; |
| aRes[I64CHARSZ] = 0; |
| for (j = 0; j < I64CHARSZ; j++) { |
| divBy10(u64a, &u64b, &u); |
| aRes[(I64CHARSZ - 1) - j] = (char) ('0' + u); |
| u64a = u64b; |
| if (isZeroU64(&u64a)) |
| break; |
| } |
| strcpy(buf, &aRes[(I64CHARSZ - 1) - j]); |
| } |
| |
| /** Convert a signed 64-bit number to ASCII. */ |
| void |
| printI64(char *buf, /* char [I64CHARSZ+1]; */ |
| const U64 * pu64) |
| { |
| U64 u64a; |
| |
| if (pu64->high & 0x80000000) { |
| u64a.high = (uint32_t) ~pu64->high; |
| u64a.low = (uint32_t) ~pu64->low; |
| incrByU32(&u64a, 1); /* bit invert and incr by 1 to print 2s complement */ |
| buf[0] = '-'; |
| printU64(buf + 1, &u64a); |
| } else { |
| printU64(buf, pu64); |
| } |
| } |
| |
| /** Convert a signed 64-bit integer from ASCII to U64. */ |
| int |
| read64(U64 * i64, const char *str) |
| { |
| U64 i64p; |
| unsigned int u; |
| int sign = 0; |
| int ok = 0; |
| |
| zeroU64(i64); |
| if (*str == '-') { |
| sign = 1; |
| str++; |
| } |
| |
| while (*str && isdigit(*str)) { |
| ok = 1; |
| u = *str - '0'; |
| multBy10(*i64, &i64p); |
| *i64 = i64p; |
| incrByU16(i64, u); |
| str++; |
| } |
| if (sign) { |
| i64->high = (uint32_t) ~i64->high; |
| i64->low = (uint32_t) ~i64->low; |
| incrByU16(i64, 1); |
| } |
| return ok; |
| } |
